This is the World of Darkness sourcebook for the UK. That may, indeed, be fairly obvious from the title, not to mention the cover image, but it still seems like a sensible place to start talking about it. Most of the authors are British, as far as I know, and quite possibly all of them. Certainly, I didn’t spot any gross errors as I was reading through, and quite a few points picked up on things that are of contemporary concern in the UK. (As far as I know from reading the Guardian website from Japan, so I suppose that Americans prepared to do research could have managed it equally well.) The proof that at least some of the authors are genuine Britons is the reference to the Wombles. Mind you, I’m not sure that I could work the Wombles into any variety of horror game.
The book was published as part of the general World of Darkness line, rather than as part of one of the subsidiary game lines. However, it reads as though it was originally written as a Werewolf supplement, and then moved after a policy decision that there would be no more regional sourcebooks for the individual games. There is a lot of emphasis on the werewolves of Britain, with details of packs and fully-statted sample members, and much less on the vampires and mages, although not nothing. There is also some material on other horrific things to be found around the UK, both from old legends and from more recent events.
On the whole, I thought it was well done. However, once again I felt that there was too much emphasis on the created characters, who could fit in, with few changes, anywhere in the world, and not enough emphasis on the background of the UK. More UK legends and haunted places, with suggestions on how to use them in stories, or tie them to different kinds of supernatural creatures, would be more to my taste. As a halfway house, maybe have some supernatural groups tied strongly to local legends, and then sketch how they might also interact with other, slightly more generic groups. This isn’t really a criticism of the authors, because they have done a good job of what they were, doubtless, told to do. It’s not even really a criticism of the editor, because I’m not absolutely sure that my idea would be an improvement. It’s more a general expression of something I think should be tried for a regional book. Until it is tried, we won’t know whether it’s actually better.